<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>JS-基本语法</title>
</head>
<body>
   
    
   <script>
    window.alert("Hello JS"); //弹出框

    document.write("Hello JS"); //写入HTML页面

    console.log("Hello JS"); //浏览器控制台
   </script>
</body>
</html>